English: Upon transfection of rapsyn-GFP NMJs maintain their normal shape and rapsyn-GFP, old and new AChRs perfectly co-localise in vivo. TA muscles of adult wildtype mice were transfected with rapsyn-GFP (green) and simultaneously injected with BGT-AF647 (‘old receptors’, blue). Ten days later, muscles were injected with BGT-AF555 (‘new receptors’, red). Then, fluorescence signals were monitored with confocal in vivo microscopy. The movie depicts a rotating 3D projection of 33 optical slices taken at an interslice distance of 800 nm. For better visibility of the different signals, only the BGT-AF647 signal shows up initially, then the BGT-AF555 signal is shown on top after the first full turn and finally the rapsyn-GFP signal is added, as indicated in the lower left corner of the movie. The depicted frame has an actual height of 81 µm. Note, that all three fluorescence signals nicely overlap and exhibit comparable extensions and intensities. Furthermore, the overall morphology of the NMJ is richly branched but contiguous.